9

Key Info Rollout 961
set a key and enter a value in the Balance Factor
field.
For example, to create a sit then walk sequence, you
could shif t the biped’s weig ht (ba lance) b etween 0
(the character is supported by the chair) for the sit
key and 1 for the stand key (the character’s pelvis
shifts to maintain balance).
If a character is seated, and reaches across the table,
leave Balance Factor at 0; however the character
leans, he will pivot from the center of mass. The
pelvis will not move back to maintain balance.
In a wa l king motion, a value of 2 will swing the
hipsandkeepthebipedheadsteady;avalueof0
will keep the hips steady and swing the upper body.
A Balance Factor value of 0 in the first image causes the biped
not to compensate for weight.
A Balance Factor value of 2 in the second image causes
the biped pelvis to move away from the Center of Mass to
compensate for weight.
The Balance Factor determines how far the biped’s
hips will shift forward or backward to compensate
for forward or backward bending of the spine.
When the biped has a normal weight distribution
betweentheupperandlowerbody,thedefault
valueof1causesthehipstoswingbackwardasthe
biped bends over to compensate for the forward
weight.
At t imes, when the biped leans, you will want the
biped’shipstorefrainfromshiftingtocompensate
for the forward weight. This would be when the
biped is sitting or fal ling down. A Balance Factor
of 0 (the minimum value) causes the hips to stay
stil l when the biped leans forward or backward.
A value of 0 places t he biped’s weight at the center
of mass. A value of 1 places the biped’s weight
above the cent er of mass. A value of 2 places the
biped’s weight in the head. C lick the s pinner up
arrow to mo ve the biped’s weight distribution
toward the head. Range=0.0 to 2.0; Default=1.
Note: You can also shif t the center of mass by
turning on Figure mode, selecting the center
of mass object, and using Rubber Band mode
(page 2–936) to move the center of mass to a new
position. This method cannot be keyframed, but
it allows you to move the center of mass outside
the biped b ody. For example, you can simulate
pushingaheavyobjectbymovingthecenterof
mass behind the biped.
Dynamics Blend—Select the Body Vertical track
(center of mass vertical track) and control the
amount of gravity in an airborne period, as in a
running or jumping motion. This p arameter has
no effect on a walking motion where footsteps
overlap.